Method of making transmission belts



A. 5. BROWN ET AL 2,391,674

METHOD OF MAKING TRANSMISSION BELTS Dec. 25, 1945.

Filed May 11, 1944' 2 Sheets-Sheet l Dec. 25, 1945. A. 5. BROWN ETAL 2,391,674

METHOD OF MAKING TRANSMISSION BELTS Filed May 11, 1944 I 2 Sheets-Sheet 2 Ivenbovs' dmisuy Patented Dec. 25, 1945 OFFICE A METHOD OF MAKING TRANSMISSION BELTS Arthur S. Brown and Gertrude E. Sedgley, Tilton, N. H.

Application May 11, 1944, Serial No. 535,078

1 Claim.

This invention relates to the making of textile transmission belts.

Endless power transmission belts have heretofore been made from tubular woven fabric by cutting sections from a length of such tubular woven fabric and then folding the edges of the section back on to the central body thereof and stitching the folded sections together to produce a belt. Endless transmission belts have also been made by taking two of such folded sections of tubular fabric and assembling them one inside the other with the folded edges of one section in contact with those of the other section and then stitching the two sections together.

In making a belt of this type, it is important that the line along which the sections of the tubular fabric are folded should be parallel to the threads of the woven tubular fabric which encircles the latter, these usually being the filling threads as distinguished from the warp threads which extend longitudinally of the tubular fabric. If in folding a section of tubular fabric the line of fold is not parallel to the filling threads so that it runs across the threads, an unsatisfactory belt will result. It is, therefore, important that the lines along which each section of the belt is folded should extend parallel to the filling threads, because when the section of tubular fabric is thus folded the strain on the belt comes in the direction of the length of the filling threads.

It is one of the objects of the present invention to provide means for guiding the operator in making the folds in the sections of the tubular fabric. This is accomplished by weaving said tubular fabric with fold-guiding lines which extend circumferentially thereof and which provide guide lines for aiding the operator in making the folds in the sections parallel to the filling threads.

Such fold-guiding lines may be made in the fabric as it is woven either by manipulating the harness on the loom to cause a harness skip according to any desired number of picks, or by employing a larger weft thread at the point where the fold-forming guide line is to be located, or by using a different colored weft thread for this purpose or in any other suitable way. Such foldguiding lines are formed in the fabric at spaced intervals along its length so that each belt-forming section which is cut from the fabric for producing a belt will have a plurality of such foldforming guide lines therein.

In order to give an understanding of the in- Vention we have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claim.

In the drawings:

Fig. 1 is a view illustrating the tubular fabric from which the belt is formed and a section which has been cut from the fabric to form an element of the belt. Fig. 2 is a fragmentary perspective view showing the section which has been cut from the fabric folded to form the outside portion of the belt.

Fig. 3 is a sectional perspective view showing a belt embodying our invention.

Fig. 4 is a perspective View of a belt made in accordance with the invention.

Fig. 5 is a diagrammatic view illustrating the manner in which one section of the tubular fabric is folded to form the outside part of the belt.

Fig. 6 is a diagrammatic view illustrating the manner in which a section of the belt is folded that forms the inside part of the belt.

In the drawings I indicates a length of tubular woven fabric from which our improved belt is i made, such tubular fabric comprising the usual with a. plurality of fold-guiding lines 2 which encircle the fabric parallel to the filling threads and which are spaced from each other lengthwise of the tubular fabric. These fold-guiding lines 2 may be made in any suitable way but will preferably be incorporated in the fabric at the time the fabric is woven. This may be done by manipulating the harness on the loom to cause a harness skip according to any desired number of picks, or by using a heavier weft thread or a colored weft thread which has a different color from the other threads of the fabric at the places where the fold-guiding lines are to be located. Any one of these procedures will produce an indication line on the surface of the fabric which is suitable for the purpose of the invention.

In making the belt one or more sections, such as the section 3, is cut from the tubular fabric I, and the edges 4 and 5 of the severed section are folded back upon the central portion thereof as shown in Figs. 5 and 6. The fabric is initially woven with the fold guide lines 2 sufliciently close together so that when any section 3 has been cut from the tubular fabric said section will have a plurality of these fold guide lines therein. In

prised of twosections=of tubuIar-fabriQwhi h;

are folded as above described and then are assembled one within the other. two sections, one section is folded so that the In folding such folded edges 4 and 5 are on the-insideofthe;

tubular section as shown in Fig. 5 and the other-- section is folded so that the folded edges -4..and 5., are on the outside of the tubular section as shown in Fig. 6.

After the two sections have been-thus folded as shown in Figs. 5 and 6, they are assembled one within the other, the section which has its edges 4 and5-located on-the outsideas-shownin Fig. 6:- beingplaced within the section which has-its folded edges locatedonthe insideas shownin.

Fig. 5. After the two sections-have been-thus assembled, theyare. secured-together in some suitable way as by means of stitching-1; The

folded-edges -4-and- 5-0f each section are thus the interior of the belt between the outside face layers-that is, therfolded edgesof eachsection contact with the-folded edges of the other sec tion. Each outside facelayer of the belt thus presents a continuous surface.

In forming the-folds of the two sections. we prefer to make one-folded edgeenarrowerthanthe other. In Fig.- 6; forinstance; the-foldsare so made that the upperfoldededgel-is narrower than thelower folded edge 5e In folding-the other section the upper folded edge-4 is-wide'r than the lower folded edge 5. This practice is employed so that when the two folded sections are assembled, the joints between the folded edges of the two sections will have a staggered relation.

With this invention in which the tubular fabric I is initially woven with the fold-guiding lines 2, the operationof correctly.fo1ding.the. sections to be employedin makingvthe'belt is greatly facilitated and a correctly folded section can be readily formed by simply making the fold either on or parallel to one of the fold-guiding lines 2.

Iclaim:

The method of making a transmission belt which comprises weaving a tubular fabric with a plurality of parallel fold-guiding threads extending circumferentially therearound at regularly spaced intervals lengthwise of the fabric, which; threads are readily distinguishable from the other threads of the fabric, cutting the tubular fabric transversely into belt-forming tubular sections with the lines of cut extending parallel to the'parallel fold-guiding threads; the spacing between'theadjacent fold-guiding threads being only a fraction of the width of each suchsection so that each tubular section has a plurality of such parallel fold-guiding threads thereon which are parallel to the edges ofthe section, folding the-edgeportions of each section back on the central portion thereof with the lines of fold extending parallel to the fold-guiding threads, assembling two folded sections by placing one within' the-other -with" the folded edges of each section contactingwith the folded edgeof; the other section andsecuring the two sections together; therebyfo rming an endless belt;

ARTHUR S. BROWN.

GERTRUDE SEDGLEY. 

